# Coding interview question patterns

##### Last updated: Nov 18, 2021

Problem | Category | Notes |
---|---|---|

Two Sum | lists, dicts | track `num:nums[i]` in dict, check if `target - nums[i]` exists |

Best Time to Buy and Sell Stock | lists, dp | Kadane's Algorithm |

Contains Duplicate | lists, dicts, sorting | list -> set and compare lengths / loop while adding to dict and check existence |

CyclicRotation | lists | loop while `insert(0, pop())` / use `colections.deque.rotate` |

OddOccurrencesInArray | lists | use `Counter` + generator expression to get the key with an odd value |

FrogJmp | - | `math.ceil(distance / possible jumps)` |

PermMissingElem | lists | linear search with `enumerate` |

TapeEquilibrium | lists | - |